Basic model with controls sited on the unit within the loft. The unit is fitted with an internal temperature sensor. This sensor continuously monitors the temperature in the loft, boosting the air volume when the loft temperature is above a set level (heat recovery mode). If the loft temperature becomes excessive the unit will switch to standby mode (no airflow). Once installed, the airflow can be set to suit the house size and, if required, the way it responds to the temperature changes within.